1. Technical Field
This present invention relates to electric field poling techniques of a ferroelectric material and, more particularly, to a ferroelectric film with a ferroelectric domain array.
2. Discussion of the Related Art
Ferroelectric materials are characterized by multi-stable states with different spontaneous polarization. These multi-stable states can coexist in a ferroelectric material to form ferroelectric domains, and the ferroelectric domains could be changed by way of applying an external electric field to the ferroelectric material.
Some special ferroelectric domains have been found to be very important to modern technologies. For example, a periodic 180° ferroelectric domain is very useful for implementing the quasi-phase matching in nonlinear ferroelectric optical materials; a ferroelectrics with two-dimensional ordered ferroelectric domains (called nonlinear photonic crystal) can provide a valuable platform to study light-matter interaction in a highly nonlinear regime; and the ferroelectric nanodomains have been found to be very useful to assemble dissimilar nanostructures. Therefore, how to form a useful ferroelectric domain, especially a ferroelectric nanodomain becomes a very critical issue.
So far, several methods have been developed for producing a special ferroelectric domain, such as the chemical in-diffusion, electric field poling method, and electron beams or writing directly with probe tips. However, the chemical in-diffusion, and electron beams or writing directly with probe tips methods have a low efficiently to produce ferroelectric nanodomains. The electric field poling method, which applies an electric field on a bulk ferroelectric material, is a common technology to produce some special ferroelectric domains, such as periodic 180° ferroelectric domains. However, it is very difficult to produce a ferroelectric nanodomain.
What are needed, therefore, is to provide a ferroelectric film with an array of ferroelectric nanodomains.